Coal drill



Jul 27,1926. 1,593,586

W. R. MEREDITH COAL DRILL Filed May 19, 1924 K/IHMerediZlz INVENTOR WITNES ES 6? M BY ATTORNEY Patented July 27, 1926.

UNITED STATES WILLIAM KYLIE MEREDITH, 0F ELDORADO. ILLINOIS.

COAL DRILL.

Application filed May 19, 1924. Serial No. 714,451.

This invention relates to an improved drill, which is especially adapted for use in mining coal, and it has particular reference to the structure of the drill head and the means for securing the bits.

The invention disclosed in the present application embodies many of the features disclosed in my earlier application, Serial No. 623,977, filed March 9, 1923, but includes various improvements thereon.

One important object of the presentinvention is the provision of a drill, which, by means of a novel arrangement of the bitsand the win 3 by which they are adjustably supporte w1ll out faster and more smoothly than those heretofore used, thereby resulting in more uniform work and reducing' the relative amount of time and labor, and consequently increasing the individual output.

Another object of the invention is the provision of improved adjustable means for securing the bits in the drill head, so that they will project to the proper distance, and will become more firmly fixed in the head as the drill is used, but may be easily removed for sharpening when desired.

The drill may be operated by a common auger brace, or itmay be driven by an electric motor or by-any other device which is commonly used for turning a drill.

The invention will be more particularly described in connection with the accompanying drawing, which illustrates the preferred form of the invention, and in which- Figure 1 is a side elevation of the drill head with a portion of the stem.

Figure 2 is a fragmentary view, partly in elevation and partly in section, of the drill head with the bits removed.

Figure 3 is a bottom plan view showing the manner in which the bits operate.

Figure 4 is a bottom plan view of the head with'the bits removed.

Figure 5 is a longitudinal section through one of the wings of the head. showing the manner in which the bitsare secured.

Figure 6 is a detail view of one of the bits and the wedge cooperating therewith.

The drill head, which is the subject of the present invention, is shown in Figure 1 as carried by an auger 10, which may be rotated in the usual manner by a common brace, or may be driven by an electric motor or other mechanical device. The head comprises four wings 11, 12, 13 and 14, radiating from the axis of the head substantially at right angles to each other, whose rearward surfaces have a slightly rearward trend substantially in the same direction as the blades of the auger 10 to which they are welded or otherwise secured. The outer ends of the wings are preferably beveled, as at 16, in the same direction as the drill bits, and recede from the center of the head outwardly, as shown at 17, to conform approximately to the bottom of the hole to be drilled.

Each wing is formed with a pair of longitudinal channels or keyways 18, adapted to receive the respective bits 19. The side walls 20 of each channel are substantially parallel.

and spaced apart a. distance equal to the width of the bits, while the front and rear,

walls 21 of each channel diverge toward the extremity of the drill, as shown in Figure 5, for receiving a bit 19, with its cooperating tapered key or wedge 22. One face of the bit is formed with serrations 23, which mate with serrations 24 formed on the tapered key 22, while the key may be placed in any position of longitudinal adjustment with respect to the bit. To insert the bit into the seat or channel 18, the tapered key 22 is first placed upon the bit with the serrations 23 and 24 in engagement, and at a sufficient distance from the cutting edge of the bit, so that the latter will project the proper distance when seated. The bit and key are then inserted in the channel 18, as shown in Figure 5, and the pressure upon the end of the drill while cutting will serve to wedge the bit more firmly in its seat. When it is desired to sharpen a bit, it may be easily'removed by tapping its inner end with mallet. The channels 18 have a rearward trend, which is preferably at a slightly greater itch than the trend of the Wing, as will e seen from Figure 5 so that the inner end of the bit will be easily accessible at one side of the auger blade.

The outer channels 18 in each of the wings are disposed at equal distances from the axis of the drill. so that when the bits are properly adjusted, the four outer bits travel in the same path, as indicated in Figure 3, and accurately define the outer wall of the -hole being drilled. Two opposite inner channels 18, as, for example, those in the wings 11 and 13, as shown in Figure 4, are located close to the axis of the drill, while the inner channels in the other two wings 12 and 14 are located farther from the center. The channels in each wing and the bits secured therein diverge from each other toward the extremity of the drill, and the extremities of the wings recede as at 17 so that in drilling, the central part of the hole is first cut, and is then enlar ed by the succeeding pair of bits, and fina lly the four outer bits cut the hole to its full size.

By reason of the manner in which the hole is formed, beginning first with a small cut near the center and progressively enlarging it, less resistance is encountered than where other types of drill heads are used. The drill never needs to be sent to the shop to be sharpened, since the miner can readily remove the bits and sharpen the cutting edges with a file or with emery. The improved method of securing the bits makes it possible to adjust the same longitudinally to compensate for the amount of stock filed or ground away, so that the drill will be of the original gage, and maintain the original diameter of the hole. The bits may also be ad'usted for holes of different diameters. A r the bits have been properly adjusted and wedged into the respective channels, the pressure on the ends of the bits, while in use, serves to wedge them in tighter, and yet they may be easily knocked out when necessary.

From the foregoing description the advantages of my improved construction will be readily apparent, and while the invention is particularly adapted for mining coal, it is obvious that the same construction may be advantageously used when drilling for other ur ses.

' e I have shown and described specifically the preferred form of the invention. it will be understood that this is merely illustrative, and that various modifications ma be made in the details of construction an the relations of the various elements without departing from the salient features of the invention as claimed.

What is claimed is:

1. A drill head comprising a plurality of radially extending wings, each having a pluralit of channels extending longitudinally t erethrough, bits secured in said channels and each terminating in a beveled edge, said wings being inclined from their outer ends rearwardly about the axis of the drill, and having their ends beveled in the same direction as the bits and gradually recedin from the center toward their periphery, t e outer ends of the inner channels in certain of the wings terminating at different distances from the axis than the inner channels of other wings, and the outer ends of the outer channels of all the wings terminating at equal distances from the axis.

2. A drill comprising an auger terminating in a plurality of radially extending wings, each having a plurality of rectilinear channels extending longitudinally therethrough, bits secured in said channels, the front and rear surfaces of said wings having a rearward trend from their outer ends rearwardly about the axis of the drill, and said channels having a greater trend in the same direction.

In testimony that I claim the foregoing as my own, I have hereto afiixed my signature.

WILLIAM RYLIE MEREDITH. 

